The invention relates to a telescopic winch for tilting a cover which closes a roof opening in a motor vehicle, with a plurality of threaded parts screwable into one another, the outermost or innermost of said parts being connected with an axially fixed wheel and the corresponding other threaded part being connected with the cover.
Telescopic winches of this type are known from German Pat. No. 2,710,193 (corresponding to U.S. Pat. No. 4,142,761) and German Offenlegungsschrift No. 2,928,994 (corresponding to commonly assigned U.S. patent application Ser. No. 170,184, filed July 18, 1980) now U.S. Pat. No. 4,428,614. These known telescopic winches are suitable only for manual operation, i.e., the wheel must be rotated in one direction or the other to tilt the cover up and down, whereupon the telescopic threaded parts, which fit into one another, are extended or retracted.
German Pat. No. 2,626,014 (corresponding to U.S. Pat. No. 4,191,068) teaches a drive means for an electrically operated sliding and tilting roof in a motor vehicle. In this known device, an electrical drive device actuates the sliding and tilting roof, whereby the drive pinion of the drive device meshes with flexible, compression-resistant threaded cables. By means of a hexagon socket, the drive pin can be actuated at the end which projects into the interior of the motor vehicle by a crank resembling a hex wrench, whereby the positive connection between the electric motor and gear reduction unit and the drive shaft is interruptable by means of a lever.
The goal of the present invention is to design a telescopic winch of the type recited hereinabove in such a manner that it is electrically actuatable and comprises an emergency actuating means.
This goal is achieved, in accordance with preferred embodiments of the invention, by virtue of the fact that a crown gear is provided on the outside jacket of the wheel, said crown gear meshing with a worm shaft of an electric motor, and by the fact that the engagement between the crown gear and the worm shaft is designed to be separable. In this manner, the invention provides electrical actuation for the telescopic winch by simple and, therefore, inexpensive means.
According to one advantageous embodiment of the invention, the wheel is removed to release the engagement between the crown gear and the worm shaft, so that the effective connection between the drive motor and the threaded part, which is otherwise connected to the wheel, is interrupted. The threaded part can then be rotated manually or with the aid of a simple tool in order to close the roof hatch.
An embodiment wherein the wheel is releasably connected with the innermost threaded part and the cover is releasably connected with the outermost threaded part is especially advantageous in this respect. In this embodiment, the innermost threaded part is rotated directly by the wheel, whereupon the outer threaded parts, disposed telescopically above the innermost threaded part, are displaced outward to open the roof hatch.
An embodiment in which the wheel is connected with the innermost threaded part by a central screw has proven to be especially advantageous. The screw can be loosened, if necessary, with the aid of a coin, for example, to remove the wheel from the innermost threaded part and thus, to disconnect the motor and the telescopic winch for emergency actuation.
Advantageously, a central polygonal recess, for example, a hexagonal recess, is provided in this embodiment in the innermost threaded part, by means of which recess the inner threaded part can be rotated with the aid of hex wrench for emergency actuation.
The special embodiments of the invention described hereinabove are especially suitable for a telescopic winch according to German Pat. No. 2,710,193 (corresponding to U.S. Pat. No. 4,142,761), wherein the cover to be actuated can be separated from the telescopic winch on the side of the telescopic winch which is away from the wheel, i.e., nearest the cover.
In embodiments in which the separation between the cover and the telescopic winch is effected by means of a pin guided centrally through the telescopic winch (German OS No. 2,928,994, corresponding to U.S. patent application Ser. No. 170,184) now U.S. Pat. No. 4,428,614, the separation between the electric motor and the crown gear of the wheel, according to one advantageous embodiment of the invention, is accomplished by virtue of the fact that the electric motor, mounted on a pivot, pivots in a manner causing its drive pinion or its worm shaft to disengage from the crown gear of the wheel.